Pole assemblies can be used for a wide variety of purposes, such as mounting signs on roadways (see U.S. Pat. No. 4,205,472), for traffic direction purposes (see U.S. Pat. No. 4,346,666), as a parking aid (such as shown in U.S. Pat. No. 5,231,392), or for clearance poles (such as shown in U.S. Pat. No. 5,474,016). For many of these pole assemblies it is desirable to have one pole element rotatable with respect to another pole element with a structure for biasing the elements to a home position. Usually biasing is provided by springs which may have hydraulic dampers. The return biasing means often can be more complicated than desired. Also, unless particularly low friction bearing elements are provided for allowing relative rotation between the pole elements, a poorly operating structure may be the result.
According to the present invention a pole assembly is provided which may have a wide variety of uses. The pole assembly is characterized by a secure construction which has relatively friction-free movement between elements thereof, and is versatile, being utilizable for a wide variety of purposes. However the most advantageous utilization of the pole assembly according to the invention is as a clearance pole, for example in drive-in restaurants or the like where it is necessary to provide a positive indication to vehicles having a height greater than a predetermined amount that they should proceed no further, yet damage is not done to the pole assembly. It is desirable that the pole assembly according to the invention comprise a clearance assembly having a yielding horizontal portion and a vertical support, the horizontal portion mounted above the ground a predetermined clearance height by the vertical support, the clearance height indicating the maximum height that a vehicle should have to attempt to move therepast. The construction according to the invention does not require any mounting structure above the horizontal clearance pole element. In the construction according to the invention the horizontal clearance element returns to a home position utilizing a simple, reliable, and effective structure.
According to one aspect of the present invention a pole assembly is provided comprising the following components: A first pole element having a first portion elongated in a first dimension. A second pole element elongated in a second dimension. The first and second pole elements mounted to each other so that the first dimension is substantially perpendicular to the second dimension, and so that the first pole element is rotatable with respect to the second pole element about an axis substantially coincident with the second dimension. And, a cam mounted to one of the first pole element and the second pole element. And, a cam follower mounted to the other of the first pole element and the second pole element, and engaging the cam. And, means for biasing the cam and the cam follower into engagement with each other so that upon rotation of the first pole element about the axis the cam and cam follower are maintained in engagement with each other.
The assembly may further comprise cooperating stops associated with the cam and the cam followers for stopping relative rotation of the first and second pole elements with respect to each other after a predetermined amount of relative rotation between them. The stops may be positioned so that rotation of the first and second pole elements is stopped after about 90.degree. relative rotation with respect to each other in either a clockwise or a counter-clockwise direction.
The cam and cam follower have an initial (home) position and the biasing means biases the cam and the cam follower into the initial position.
The first pole element preferably includes a second portion elongated in the second dimension, and mounted so that it is substantially concentric with a second pole element, and the biasing means preferably comprises means for stationarily mounting the second pole element so that the second dimension is substantially vertical so that gravity biases the cam and cam follower into engagement with each other, and so that the first dimension is substantially horizontal. Alternatively the biasing means may comprise a wide variety of conventional spring elements, or hydraulic or pneumatic cylinders.
Preferably a dry lubricant is provided between the second element and the second portion of the first element to provide relatively friction free rotation thereof with respect to each other. The cam follower preferably comprises a block of material having an angled face making an angle of between about 30-70.degree. with respect to the second dimension, the angled face directly engaging the cam. The cam may comprise a rod, tube or bar having an desired cross-section, but preferably being substantially circular in cross-section and extending substantially perpendicular to the second dimension and having an exterior surface. The exterior surface is engaged by the angled face. Preferably the block of material is of, or the angled face has an edge engaging the cam that is coated with, a low friction material. Preferably the block is ultra-high molecular weight polyethylene. Preferably the cam follower is stationarily mounted to the first pole element second portion, and the cam is stationarily mounted to the second pole element. The first pole element first portion is preferably positioned above the ground a predetermined clearance height indicating the maximum height that a vehicle should have to attempt to move past it.
According to another aspect of the present invention a clearance pole assembly is provided comprising the following components: A first pole element having a first, substantially horizontal, portion, and a second, substantially vertical portion. A second, tubular, pole element stationarily mounted to the ground and extending substantially vertically and receiving the first pole element second portion therein and mounting the first pole element first, substantially horizontal, portion above the ground a predetermined clearance height indicating the maximum height that a vehicle should have to attempt to move therepast. The first and second pole elements mounted so that the first element is rotatable with respect to the second element about a substantially vertical axis substantially concentric with the second pole element. And, return means for returning first and second pole elements to a home position with respect to each other, while allowing rotation of the pole elements with respect to each other from the home position, the return means comprising a cam stationarily mounted to the second pole element and a cam follower stationarily mounted to the first pole element second portion, gravity biasing the cam follower into contact with the cam.
The details of the components, and their particular construction, preferably is as set forth above.
According to yet another aspect of the present invention a clearance pole assembly is provided comprising the following components: A first pole element having a first, substantially horizontal, portion, and a second, substantially vertical, tubular portion, the first portion having clearance indicia thereon. A second, tubular, pole element stationarily mounted to the ground and extending substantially vertically and receiving the first pole element second tubular portion therein and mounting the first pole element first, substantially horizontal, portion above the ground a predetermined clearance height indicating the maximum height that a vehicle should have to attempt to move therepast. The first and second pole elements mounted so that the first element is rotatable with respect to the second element about a substantially vertical axis substantially concentric with the second pole element. A tubular extension of the first pole element first portion, extending downwardly therefrom and having a lower surface. The second, tubular, pole element having an upper surface which mates with the lower surface of the tubular extension, an interface provided between the upper and lower surfaces. A collar fixed to the tubular extension and extending downwardly therefrom and exteriorly concentric with the second pole element, the collar covering said interface. The first and second pole elements have bearing surfaces engaging each other, including distinct bearing surfaces that are vertically spaced from each other. And, a dry lubricant disposed on the bearing surfaces for facilitating low friction rotation of the first pole element second portion with respect to the second pole element about the axis.
It is the primary object of the present invention to provide a simple and effective pole assembly, desirably one that is effective as a clearance pole assembly. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims.